1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
|
/*
NetWinder Floating Point Emulator
(c) Rebel.com, 1998-1999
(c) Philip Blundell, 1998-1999
Direct questions, comments to Scott Bambrough <scottb@netwinder.org>
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include <linux/module.h>
#include <linux/version.h>
#include <linux/config.h>
/* XXX */
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/signal.h>
#include <linux/sched.h>
#include <linux/init.h>
/* XXX */
#include "softfloat.h"
#include "fpopcode.h"
#include "fpmodule.h"
#include "fpa11.h"
#include "fpa11.inl"
/* external data */
extern FPA11 *fpa11;
/* kernel symbols required for signal handling */
typedef struct task_struct* PTASK;
#ifdef MODULE
int fp_printk(const char *,...);
void fp_send_sig(unsigned long sig, PTASK p, int priv);
#if LINUX_VERSION_CODE > 0x20115
MODULE_AUTHOR("Scott Bambrough <scottb@rebel.com>");
MODULE_DESCRIPTION("NWFPE floating point emulator");
#endif
#else
#define fp_printk printk
#define fp_send_sig send_sig
#define kern_fp_enter fp_enter
#endif
/* kernel function prototypes required */
void fp_setup(void);
/* external declarations for saved kernel symbols */
extern void (*kern_fp_enter)(void);
/* Original value of fp_enter from kernel before patched by fpe_init. */
static void (*orig_fp_enter)(void);
/* forward declarations */
extern void nwfpe_enter(void);
/* Address of user registers on the kernel stack. */
unsigned int *userRegisters;
void __init fpe_version(void)
{
static const char szTitle[] = "<4>NetWinder Floating Point Emulator ";
static const char szVersion[] = "V0.95 ";
static const char szCopyright[] = "(c) 1998-1999 Rebel.com\n";
fp_printk(szTitle);
fp_printk(szVersion);
fp_printk(szCopyright);
}
int __init fpe_init(void)
{
if (sizeof(FPA11) > sizeof(union fp_state))
printk(KERN_ERR "nwfpe: bad structure size\n");
else {
/* Display title, version and copyright information. */
fpe_version();
/* Save pointer to the old FP handler and then patch ourselves in */
orig_fp_enter = kern_fp_enter;
kern_fp_enter = nwfpe_enter;
}
return 0;
}
void __exit fpe_exit(void)
{
/* Restore the values we saved earlier. */
kern_fp_enter = orig_fp_enter;
}
/*
ScottB: November 4, 1998
Moved this function out of softfloat-specialize into fpmodule.c.
This effectively isolates all the changes required for integrating with the
Linux kernel into fpmodule.c. Porting to NetBSD should only require modifying
fpmodule.c to integrate with the NetBSD kernel (I hope!).
[1/1/99: Not quite true any more unfortunately. There is Linux-specific
code to access data in user space in some other source files at the
moment (grep for get_user / put_user calls). --philb]
float_exception_flags is a global variable in SoftFloat.
This function is called by the SoftFloat routines to raise a floating
point exception. We check the trap enable byte in the FPSR, and raise
a SIGFPE exception if necessary. If not the relevant bits in the
cumulative exceptions flag byte are set and we return.
*/
void float_raise(signed char flags)
{
#ifdef CONFIG_DEBUG_USER
printk(KERN_DEBUG "NWFPE: %s[%d] takes exception %08x at %p from %08x\n",
current->comm, current->pid, flags,
__builtin_return_address(0), userRegisters[15]);
#endif
float_exception_flags |= flags;
if (readFPSR() & (flags << 16))
{
/* raise exception */
fp_send_sig(SIGFPE, current, 1);
}
else
{
/* set the cumulative exceptions flags */
writeFPSR(flags);
}
}
module_init(fpe_init);
module_exit(fpe_exit);
|
